Sleep apnea syndrome (SAS) is a disease characterized by multiple episodes of cessation of respiration (apnea) during sleep, resulting from partial or complete obstruction of the airway by the root of the tongue and/or the soft palate falling down therein. As a result, sleep is disturbed and daytime sleepiness occurs; in recent years, a large number of accidents attributable to this disease, including driving a car asleep, have been reported.
Traditionally, a measure against sleep apnea syndrome has been taken, in which the lower jaw is slightly drawn (pulled) forward from the normal occlusal position to forcibly maintain an airway, so as to prevent apnea during sleep. The lower jaw is usually drawn forward using a dedicated airway maintenance apparatus (hereinafter sometimes referred to as “mouthpiece”) set in the oral cavity.
As such a mouthpiece, for example, one disclosed in patent document 1 is known. This mouthpiece comprises an upper-jaw side attachment to be attached to the upper jaw side (referred to as “upper mold” in patent document 1) and a lower-jaw side attachment to be attached to the lower jaw side (referred to as “lower mold” in patent document 1), and has a structure in which the lower-jaw side attachment is fixed in a unified way to the upper-jaw attachment with a shift toward the front face side from the normal occlusal position.
In addition, for example, one disclosed in non-patent document 1 is also known. This mouthpiece comprises an upper-jaw side attachment and a lower-jaw side attachment in a separable way, and has a structure in which the attachment position of the lower-jaw side attachment to the upper-jaw side attachment can be adjusted stepwise.
An airway is maintained by drawing the lower jaw forward using the mouthpiece disclosed in patent document 1 or non-patent document 1.
Patent document 1: Japanese Patent Unexamined Publication No. HEI-7-241341
Non-patent document 1: Catalogue of Panasonic Dental Co., Ltd., “Anti-snoring Mouthpiece Thrasnore™” Internet <URL: http://panasonic.co.jp/healthcare/dental/products/pdf/therasnore.pdf>